Updated

The Maldives government on Thursday disputed claims by the Japanese foreign ministry that a Maldivian-flagged ship transferred goods to a North Korean-flagged tanker at sea in violation of a U.N. Security Council resolution.

A Japanese foreign ministry statement said a Japan Maritime Self-Defense Force aircraft last week spotted a North Korean-flagged tanker alongside Xin Yuan 18, a Maldivian-flagged tanker, in the East China Sea. The statement on Tuesday said Japan "strongly suspects that they conducted ship-to-ship transfers banned by UNSCR."

The Maldives Democratic Party, an opposition political party in Maldives, said in a statement Thursday that Xin Yuan 18 is registered in the Maldives and that "it is believed that the vessels were exchanging crude oil, in violation of UN sanctions on North Korea."

The Maldives president's office said in a statement that the vessel was never registered in the country.

A separate statement by the Maldives foreign ministry said Maldives does not allow a flag of convenience to foreign-owned vessels to operate outside Maldivian waters and that any use of a Maldives flag violates its laws. It also said the government condemned the use of its national flag.

It also said Maldives "gives high priority to the implementation of all resolutions of the United Nations Security Council," including resolutions on North Korea.

This latest development comes amid mounting criticism against the Maldives government for declaring an emergency and arresting judges, opposition politicians and activists in political turmoil that has engulfed the Indian Ocean archipelago nation for weeks.

On Feb.1, the Supreme Court ordered the release of a group of President Yameen Abdul Gayoom's political opponents who had been imprisoned.

The state of emergency gives wide powers to security forces to detain people and curtail freedom to protest. Yameen had two Supreme Court judges arrested, accusing them of corruption. Later, the remaining three judges annulled the order.

Maldives became a multiparty democracy in 2008 after decades of autocratic rule. Yameen has rolled back much of the country's democratic gains since being elected in 2013.